Water is heavily used in industrial, commercial and residential settings during the preparation of food including the cleaning of containers, cookware and utensils used in cooking. This produces a consequent amount of waste water which typically contains a substantial amount of organic matter, including solid particulate matter and grease. Grease which enters the public sewage system may be treated at sewage treatment plants at a substantial cost. In industrial and commercial settings, some local governments mandate the use of grease trap collection units to minimize the volume of grease entering the public sewage system.
The construction of grease traps is known in the art. Standard grease trap collection units consist of settling tanks for the collection of grease and other organic matter. The grease trap collection units are typically positioned as part of the waste water flow path from the source of the waste water (eg. a kitchen) to, eg., a municipal waste water line. The grease trap collection units may not separate grease from the waste water efficiently as the flow therethrough deters the settling out of the grease. As grease and solid particulate matter build up in the grease trap, the efficiency of the grease trap tends to decrease.
Excessive grease in waste water systems may result in excessive bacteria, may attract vermin or insects, may cause blocked pipes and reduced flow rates in sinks, and may allow noxious odours to enter a kitchen through waste water drains. Accordingly, standard grease trap collection units may require the regular service of a grease removal specialist to empty the trap and dispose of the grease and other matter that has built up therein.
European patent application No. 0,373,048 to Deshayes teaches a waste water filter unit having a filter inside a collector body, for removing solid organic matter from waste water. This filter unit works on a principle similar to that of a conventional grease trap, wherein particulate matter either floats to the top, or settles to the bottom of the water held in the collector body. Instead of using baffles to prevent the agitation of water moving through the collector unit, a non-deformable filter bag is used to retain the particulate matter.
European Patent Application No. 0,687,493 to Passavant-Werke AG teaches an apparatus for recycling organic compounds from sewage. The apparatus comprises a collector body containing either a solid, drum-like screen cage which is lined with a filter bag or a filter bag which sits on structural supports, and a pump for pumping the filtrate back into the collector body.